A Reply to an Angry Dendroclimatologist

In a recent post, I challenged the Dendro Truth Squad to root out use of precipitation proxies in multiproxy studies (which the NAS Panel also encouraged avoidance of). Instead of illustrating this with bristlecones one more time (although they obviously occur in a high desert), I illustrated the challenge with the example of Dulan junipers, located in a high dry desert in China. This prompted the following anonymous response from an angry dendroclimatologist via our valued occasional correspondent, Rob Wilson, saying:

A second case in point is the broad Project for the Dendro Truth Squad’ stone you hurled up on this page. Those in the know, who really know the science, know not to use that chronology and know who still use that chronology. The work that uses that chronology for a temperature reconstruction is less-respected than others. Please, do not cast the whole field as deceitful or ignorant of this. You state that it is not your intention to slander the whole science, but why post the picture of that tree and make road statements, make a separate post about it and string a long list of papers that use that chronology if you are not trying to undermine the science? Why not post the longer string of papers that DO NOT use that one site? The final point, you and others are beating some extremely dead horses. The people and papers you audit’ is very selective. You ignore more recent work that surpasses others.

“Recent work that surpasses others”. The mouth waters at the thought. One almost expects to hear the Hallelujah Chorus playing as rose petals are strewn in the path of the work that surpasses all others. How could I have overlooked the work that “surpasses” all others? I emailed Rob to identify the work that “surpasses” all others so that I too could come and adore it.

Would it be in a humble dwelling or a royal palace? Actually I was wondering about something more mundane: did it use bristlecones or foxtails? Did it use Yamal or Polar Urals? I realize that these are pretty mundane question when you’re supposed to be adoring and the Hallelujah Chorus is playing at full volume with a 2500-member choir (the assembled IPCC scientists).

I could hardly wait for Rob’s answer. Disappointment. Rob said that he didn’t know which studies his friend had in mind and had no personal suggestions. He was merely relying comments from his friend and don’t shoot the messenger. Anyway, angry dendroclimatologists, if you know of a study that “surpasses all others”, please tell me so that I too can come and adore it.

As to the dendroclimatologist’s accusation that I’ve been “selective” in the studies that I’ve discussed, I can hardly think of a more ridiculous accusation. I’ve discussed virtually every multiproxy study at one time or another: not just MBH, but Crowley and Lowery 2000, Jones et al 1998, Briffa et al 2000, Esper et al 2002, Moberg et al 2005, Osborn and Briffa 2006, Hegerl et al 2006, plus many proxy studies including ocean sediments, alpine lake sediments, you name it. I’m trying to understand the evidence; if there’s something relevant, I’m interested. I’m particularly interested in studies that are supposed to be definitive. I’m not trying to pick on the worst studies; I’m trying to focus on the best studies. MBH was supposed to be the best so that’s what I looked at. I didn’t look at it because it was supposed to be the weakest. If there’s something interesting that I should be aware of, I’m all ears. I’d love to read the recent work that “surpasses” all others and I’ll be happy to discuss it here. So any dendroclimatologists out there – if there’s something that I’m overlooking, I’ll look at it. (And yes, twq, I tracked down Gou et al 2007, which is barely off the press and will talk about it, but it would be nice if dendroclimatologists were not always “moving on”.)

I found the following statement from the angry dendroclimatologist particularly repugnant:

Those in the know, who really know the science, know not to use that chronology and know who still use that chronology.

IPCC is obliged to use “peer reviewed” articles. So it’s not enough for “those in the know, those who really know the science” to be aware of the problems. They can’t operate like a type of masonic order with secrets reserved for the elect. If “those in the know, who really know the science” know that there is a problem with using a certain chronology as a temperature proxy, then they have a responsibility to enter that knowledge into the literature. If for some reason, they’ve attempted to do so and publication was thwarted, then they had responsibility as IPCC reviewers to enter that knowledge into the IPCC review process. As an IPCC reviewer, I exercised my right to obtain all review comments of chapter 6 of the First Order Draft and I can tell you that no dendroclimatologist made such a comment in the review process.

Secondly, I did not slander dendroclimatology by listing papers that directly or indirectly used Dulan junipers as a temperature proxy. Truth is a defence to slander and it is a matter of fact – uncontested by our correspondent – that Dulan junipers were used directly by Crowley and Lowery 2000 as a temperature proxy and indirectly via the Yang composite in the other listed papers. Yes, there are papers that don’t use Dulan junipers either directly or via the Yang composite, but the list is about the same length and these latter papers all use bristlecones and foxtails. The salient point is that IPCC uses papers that are apparently “less well-respected” without telling us which ones they are. (BTW I’m not arguing here that the presence/absence of Dulan junipers has a material impact on these reconstructions; however, the presence/absence of bristlecones/foxtails, also from high desert, obviously do have a material impact on many reconstructions, as does such trivial permutations as the use of Yamal versus Polar Urals on others.)

I have never said or suggested that the whole field is “deceitful” or “ignorant”. I’ve reported favorably on a number of dendro articles – Wilmking et al 2004, 2005; Driscoll et al; Naurzbaev et al 2004 (including Hughes); Miller et al 2006; some Russian articles. I’ve even said that D’Arrigo et al 2006 is a much better article than the more prominent Osborn and Briffa 2006 (which is heavily applied by IPCC 4AR). Martin Wilmking has written in, agreeing that my coverage of his articles was timely and fair and expressing confidence that I would report work that supported the Team as well as work that didn’t.

Words like “deceitful” and “ignorant” are words that are used in tort law. To the best of my recollection, I’ve never used either word in connection with angry dendroclimatologists and neither really expresses my views (although I would be hard-pressed to think up a complimentary adjective to describe the 1960 truncation of the Briffa et al 2001 reconstruction in IPCC TAR). People have obligations and duties beyond merely not being “dishonest” or “ignorant”. Drawing from my own experience with public disclosure in mining business, I’ve suggested that scientists have duties of “full true and plain disclosure” and of due diligence, neither of which are exhausted by merely not being “dishonest” or “ignorant.”

The IPCC said that additional proxies show “coherent behavior”. Yet we see all sorts of discordant behavior in dendroclimatology – not just between sites, but, as Wilmking and Pisaric have shown, even within individual sites. IPCC 4AR did not cite Wilmking or discuss the problem. Did dendroclimatologists acting as authors or reviewers have an obligation to identify these problems? Yes or no. If they did, why didn’t they do so? Until these and related divergence problems are sorted out, IPCC should place very specific caveats on dendroclimatological results that go well beyond any of the caveats in the Second Draft and are inconsistent with the SPM claim of “coherent behavior”. If dendroclimatologists acting as authors and reviewers don’t bring out these issues and problems, then they can hardly complain when people question how they discharged their duties in the IPCC process.

Gou et al 2006

Here’s another interesting twist to the angry dendroclimatologist’s claim that: “Those in the know, who really know the science, know not to use that chronology [the Dulan juniper chronology of Wang et al 1983]”. It turns out that the circle of the elect appears to exclude well-known dendroclimatologists Gordon Jacoby and Edward Cook.

Here is a plot of the Dulan juniper series from the smoothed version used in Crowley and Lowery 2000 (just so you get your eye in.) We do not consider here the question of whether this particular series is a plausible proxy for temperature (and, given the undoubted evidence that temperatures rose in the 20th century, as well as the nearby desert, one might at least raise an eyebrow as to whether this is a plausible temperature proxy).

Figure 1. Plot of email data from Crowley for Crowley and Lowery 2000. The citation for this series is Wang Yuxi, Liu Guangyuan, Zhang Xiangong Li Cunfa: 1983, The relationships of tree rings of Qilianshan Juniper and climatic change and glacial activity during the past 1000 years in China, Kexue Tongbao, 28(12):746-750.

Now here is the top panel of Figure 3 from Gou et al [Ann Glac 2006]. I draw your attention to the top series, which has a rather similar shape to the Crowley and Lowery 2000 series although the Crowley and Lowery has a 20th century uptick not present in the top panel – more on this later). Gou et al 2006 say that their top panel is a “tree-ring width chronology from Tianjun, Qilian Shan”, citing Yang B 2003. Adv. Earth Sci., 18(2), 285—291, an inaccessible publication. Tianjun is near Dulan (you can see it in the Shao et al PAGES location map.)

While this particular Yang B publication is inaccessible, I located two other publications by Bao Yang in 2003: Yang, B. et al [Quat Sci Rev 2003] and Yang, B. et al [Chin Sci Bull 2003]. Both of these publications included panel drawings with a Tianjun tree ring series as shown below.

This is obviously the same series as the one illustrated in the top panel of Gou et al 2006. This series also looks like the Crowley and Lowery version (other than the 20th century uptick in the latter) and, like Crowley and Lowery 2000, is attributed to Wang et al 1983.

Now there is much else to be said about the original Wang et al 1983 series, which turns out to be based only three cores from south-facing sites north of the Qaidam depression – with one of the cores being taken about 150 km away from the other two. Wang et al give locations of their cores which prove to be close to sites studied in Shao et al 2004 and described by them as spring precipitation proxies. I’ll get to that on another day.

However, going back to the original Crowley version. It is indisputably a version of the same series as the one used in Yang et al 2003 and Gou et al 2006, but it contains a 20th century uptick that is absent in the Chinese versions. What is the basis for this? Unfortunately we won’t know because Crowley “misplaced” the original version of his data. (The actual plot in Wang et al 1983 is actually a little different again than either version.)

The point today is this: if Rob Wilson’s angry dendroclimatologist friend is right and “those in the know”, those “who really know the science”, know not to use this particular series as a temperature proxy, then its use by Jacoby and Cook can only mean that Jacoby and Cook are not yet 12th-order masons. Maybe Rob’s friend should let them in on the secret handshake.

Standard (flawed) debate tactic: claim your “rival” isn’t looking at the big-picture, or only selectively reviewing evidence, then dismiss his entire argument by noting there are other “better” methods in spite of the fact that none can be cited. It is sort of a sleight of hand.

If the angry dendro’s arguments are so compelling, why do they not address the arguments Steve M. has made head on? IMO, they can’t.

Yes, this is a very common tactic used to defend bad science. Another related tactic is to say or imply that the science that proves something is so complex that only a select few can understand it. The RC blog seems to have this approach down to an art form where they present arguments with virtually incomprehensible language and technical jargon, while liberally throwing around words like debunked, refuted, etc., to characterize arguments from critics.

Actually, come to think of it, I used to do that when I was a kid. When my little brother would figure out that something I said was wrong (and this bugged me), I would try to dress up my language with words and bafflegab he didn’t understand to try and make my argument sound more authoritative… like I really knew what I was talking about. Didn’t take him long to get wise to this tactic.

A set of related questions: Does there exist a dataset like the CRU instrumental temperature records for precipitation? Is it possible to calculate a global precipitation index annually? Or even regionally? What I’m getting at is if the temperature and precipitation variables are tangled in complex ways, why don’t we see the instrumental precipitation records paired up with the temps? The two together should be compared to tree-ring chronologies, shouldn’t they?

It is usually easy to find examples of poorly conducted research within any scientific field. In academic circles it is very much a case of “publish or perish” so unfortunately corners sometimes get cut a bit and this does not always get filtered out by the peer review process because the people reviewing the papers tend to have a very busy schedule due to research, teaching and family commitments and cannot, therefore, devote the same amount of time on ferreting out all the problems that a retired person can. Nothing should be read into the fact that dendroclimatologists do not come on here to publically criticize their colleagues than the fact that that colleague may well be reviewing one of their papers or grant applications in the not too distant future so needlessly antagonizing them is not a good career move. The fact these problems are not typically dealt with in that sort of gladiatorial manner in academic circles should not be taken as a sign that they are ignored. The number of times a paper is ever actually cited in the years after it is published is often the best yardstick in determining how seriously a data set is taken.

It seems to me that there is a danger that if only the very worst papers on one narrow aspect of the scientific case for AGW are cherrypicked for “audit” on here, while other key fields that relate to the issue of climate change like the IR spectroscopy of atmospheric CO2 are ruled as being completely inadmissible in terms of commenting on this blog, that people with a limited scientific background, could easily be given a false impression as to the overall validity of the science conducted in the field of climate change. It should be noted, for example, that there have been dendroclimatology studies that would tend to undermine Mann’s hockey stick and which would therefore tend to fit in with the large body of historically documented evidence for the LIA and MWP:-

Larson and Kelly (1995) have discovered that the growth of cliff-face white cedar from the Niagara Escarpment is extremely temperature-dependant and can be used as a proxy mean summer temperature record for southern Ontario. A 2,791 year paleoclimate record has been established. This record indicates a general warming trend has occurred since about 1960 with the last decade being particularly warm. This followed a period of slightly cooler than normal temperatures of about the same duration. While unique to this century, and therefore reflected in the recorded climate record, this fluctuation easily falls within the observed prehistoric limits. A much more dramatic fluctuation occurred between about 1550 and 1600 and equably abrupt fluctuations occurred at the beginning of the chronology, about 600 BP. Therefore the recent trend towards warmer temperatures must be both longer and warmer before it is unique for Ontario.

I would suggest that the good should maybe be highlighted as well as the bad and that the aggressive tone of the opening sentence and last paragraph in this particular entry should probably be dropped if the aim is to actually engage these people in debate rather than to simply ridicule certain aspects of their work in no great expectation of ever receiving a direct response.

…there is a danger that if only the very worst papers on one narrow aspect of the scientific case for AGW are cherrypicked for “audit” on here,…

Apparently you believe that only the very worst ARE “audited” here (otherwise your implication is just a straw man). I’m sure most of the readership here would appreciate references to those non-“very worst” papers that you believe are being ignored here.

As for the citation yardstick you mention, it would seem that such a yardstick would imply that the various Mann reconstructions (for example) are taken very seriously.

Why should that paper be considered ‘good’, and thus worthy of some concilliatory praise?

On the basis of its results – that they comport with what you think should be the preconcieved position of the commentors on this blog? Thats the way the Team works, not CA.

Data. Methods. Reasoning. Science is only famously self-correcting when faults in those are exposed. Not merely when faulty works are less frequently cited by ‘those in the know’. ‘Those in the know’ need to educate ‘those who oughta know better’ in full view of ‘those that dont know’ lest the latter persist in being ‘those that know wrong’.

9, JohnM: You make some good points, but I don’t think Steve M is cherry-picking poor papers. He may be concentrating on ones that look suspicious, because of the use of certain proxies that are known to be problematic. He cannot audit all papers, after all.
What I cannot understand is why the dendro community keeps publishing such dubious papers.

Regarding other key fields in climate change studies, I wish more effort could be expended in auditing the GCMs, since it seems to me that they are now about the only things that support a large AGW effect. Do you think these models form a sound basis for policy decisions?

RE: #13 and #9 – The simple fact is that in the so called “Climate Sciences” field, poor, exagerated publications, using dumpster dived or manipulated “data” tend to be in the majority. So much low hanging fruit, so little time ….

Your comments on the publication system strike right at the core of the issue. I’ve commented here before about the “inconsequential sloppiness” of the publication system, which is exactly what you’re talking about. But you can’t have your cake and eat it too. Either one can rely on peer-reviewed papers, or one can’t. If it becomes a matter of knowing which papers are good and which aren’t, then we’re completely in the dark because the judgment will depend on who’s the judge. If, then, the IPCC makes claims for objective scientific truth because it is based on peer-reviewed papers, how can we believe them? This is actually a very serious issue, one that has been hotly debated by philosophers and sociologists for the past 4 decades ever since Kuhn. Now here we have a very practical example of it. You have a group of scientists who claim on the one hand to be producing a report based on peer-reviewed litterature that has an absolute “truth” value, and, when pushed in a corner, admit that the peer review system isn’t up to scratch because reviewers are too busy. It just doesn’t compute and there’s no easy way out. In normal circumstances, as I have said before, nobody would care. But these are not normal circumstances. These are circumstances where people have an interest in seeing one side or the other “win”, based on ideological reasons, and that, unfortunately, includes the scientists themselves, or at least some of them. So we clearly need some higher standards of quality and objectivity, otherwise the whole enterprise has no credibility. That is what Steve is promoting, nothing else, nothing more. I think your best defense would be to stick to the issue as he does, and give straight answers to straight questions. It’s not enough to hide behind your expertise. We ALSO want to know. Actually, this being a matter of puclic interest, we DESERVE to know.

I would like to comment a bit on the social aspects of bad science
by way of an example.

About 20 years ago, physics went through a fifth-force episode.
Basically, evidence was presented that gravity had a short-range
component that was not 1/r^2. Now this was based on some rather
shoddy work. I happened to know a grad student working in the
field gravity measurements. Two things were apparent
(i) They thought the work that gave the the short-range component
was rather slipshod and sloppy.
(ii) They were not going to really nail the guys who did it. Due
to the publication in peer-reviewed journals there really was an
upsurge in interest in doing measurements in “g” and “G”. So
there was a lot more money flowing around the field. This
was great!

Well, our group did their experiments, and said “We do not see
any fifth-force” in a nice and polite and collegial manner. The eventual
outcome was that the fifth-force faded into obscurity when the original
promoters of the force very carefully self-audited their own work,
found their mistakes and then published them.

I suspect something similar is happening here, but without the
correcting mechanisms coming into play, and making the problems
worse is the fact that it is happening in the area of public
policy.

(i) The whole AGW thing means there is a lot more money around.
(ii) I suspect the Dendro research community has benefitted from
the money.
(iii) Even if some people have doubts about the work of the
Hockey Team, they are not voicing those doubts in a public manner,
or really trying hrad to prove stuff wrong. The angry email seems
to indicate that there are people in the community who know there
are published items that are garbage, but do not judge “us” by
“them”.
(iv) Unfortunately, SteveM is forcing a confrontation. Basically,
what he is doing is essentially judging the Dendro by community
by “them”, since as far as he is concerned, the public voice of the
Dendro community is essentially been driven by “them”.
(v) If this was purely an Academic matter it would be small potatos.
However, the public policy implications of the past climate record
are large. This means a quiet life as an academic is harder to
achieve and it is more difficult to just sit on the sidelines.

So if the Denrdo community know of instances of proxies being
used inappropriately, then it will be necessary to actively
correct them, by writing a comment, and not necessarily in
a manner that is polite and collegial. Neutrality may not
be an option.

It seems to me that there is a danger that if only the very worst papers on one narrow aspect of the scientific case for AGW are cherrypicked for “audit” on here, while other key fields that relate to the issue of climate change like the IR spectroscopy of atmospheric CO2 are ruled as being completely inadmissible in terms of commenting on this blog, that people with a limited scientific background, could easily be given a false impression as to the overall validity of the science conducted in the field of climate change.

I really don’t try to cherry pick the “very worst papers” in this field. I’ve given the most attention to the most influential papers. I looked at MBH originally, not because I thought it would be the worst, but because it was the most influential, it was supposed to be the best and no one had ever checked it.

I don’t blame journal peer reviewers for the very cursory due diligence carried out on articles prior to scientific publication. My point is that the public and other scientists should recognize that journal peer review is a minimal form of due diligence and much less than is done for small stock offerings by obscure mineral exploration companies. Given that journal peer review is so cursory (with family obligations of reviewers and all that), it nevertheless seems to me that there still should be some method of improved due diligence and verification before weak studies are incorporated into policy documents. The easiest way to improve due diligence standards is for journals to require authors to archive data as used and code so that their studies are easily replicable – by reducing the hurdles to replication, you should be able to achieve much improved assessment of studies. Any arguments against this strike me as cliamte scientists trying to suck and blow – if policy is to be based on these studies, then authors cannot be primadonnas and must be required to disclose their data and methods.

I got interested in HS studies because, as you know, the “warmest in a 1000 years” was widely used in Canadian government promotions and the HS was a prominent feature in TAR. I quite realize that there are other relevant issues in the AGW debate and that the impact ultimately depends on infrared and water vapor. It would take me at least a year of solid work to put myself in a position where I could comment on these matters with the competence that I would like to have prior to saying very much on them. If any physicists want to submit threads here, the door is open. I post on proxies mostly because I’m interested in them and I’m learning as I go. There are interesting statistical issues which I try to reflect on as well.

If the paleoclimate arguments are not relevant to policy, then IPCC should have removed this chapter from AR4. In my capacity as a reviewer, I suggested this. From a policy maker’s point view, if the argument is not important or relevant, then why use it? However this (IMHO) sensible suggestion to IPCC was rejected. The “consensus” was to include the paleoclimate arguments and, if anything, endorse the HS once more. I thought that the IPCC AR4 section on millennial climate was unbalanced, and suffered because the lead author had a horse in the race. He even prominently featured a graph from his own recent article, as Mann had done before him. So yes, I’m going to keep criticizing IPCC on their proxy studies.

Does that leave an unbalanced and poor impression of IPCC? Perhaps – but they could and perhaps should have avoided the issue by simply not getting into the paleoclimate arguments if they are not relevant.

The trouble for me in assessing their credibility on other matters is that, in this one area that I’ve researched, IPCC has continued to endorse articles that, in my opinion, are seriously flawed; their flaws were known or should have been known to IPCC and yet the articles continue to be cited and relied on. If this is the form of quality control or lack of quality control in the area that I have experience, how can I reasonably assume that their quality control and due diligence in other areas is any better or that the studies are any better? I’m not saying that these other studies are bad because it would take me a very long time to arrive at an opinion one way or the other; my point is that the due diligence processes do not even meet the standards required for mining promotions and therefore it’s tough to rely on IPCC endorsement in an intellectual sense. This is different from a policy sense: as I’ve said many times, if I had a big policy job, I would be guided by the views of official institutions such as IPCC rather than my own personal views, but I would also do what I could to improve proxesses of disclosure and due diligence and try to ensure more focused research so that there would actually be some progress in narrowing the confidence intervals of the impact of 2 xCO2, which have not changed in 30 years despite all the research.

#9. Larson and Kelly are at the University of Guelph and Ross McKitrick and I spent a very interesting day with them in summer 2004 discussing cedars and bristlecones. Their view was that long-lived cedars tended grow about the same under a variety of conditions, but liked cool moist summers – the botanists’ upside down U-curve that we’ve talked about on the blog. They thought that dendrochronologists tended to pay insufficient attention to site ecology and thought that Hughes’ concept of a “natural archive” was not an apt metaphor for tree rings. Larson and Kelly were both smart guys; I’ve read many of their articles and try to be consistent with their viewpoints.

#8. yes, there are collections of precipitation data just as there are collections of temperature data. I’m not as familiar with it though I’ve looked at some data sets when I was trying to locate Mann’s precipitation data.

#22 – Please tolerate my ignorance a bit more and tell me if there is a way to statistically estimate the relative contributions of precipitation and temperature to tree-ring data if all three variables are available for a single tree or a composite of tree chronologies, assuming of course that other factors are minimally influencing tree growth.

You claim that those “in the know”, know which papers are faulty and don’t cite them, so there is no need to tell the rest of the world.

The problem is that the rest of the world assumes that any paper that is peer reviewed must be good. Then they use these faulty papers
as a basis for their own work. Such as the in the climate change debate.

The result is that your desire to protect your peers from criticism that might hurt their feelings ends up being support for bad policy
based on bad data.

That’s not good. The implications of Kyoto go way beyond the feelings of a handfull of dendroclimatologists.

Those in the know, who really know the science, know not to use that chronology and know who still use that chronology. The work that uses that chronology for a temperature reconstruction is less-respected than others

I’ve asked this before: Please, please: Can we lay readers have a reference? So we too can see both sides? Please?

The anonymous dendro deserved every bit of this hard-hitting satire… and more.

The simple fact that is sitting in the open here is that the peer-review system turns academic scientists into cowards. Why challenge the prevailing opinions when you have to submit your grant application and journal article to those that hold the prevailing opinions? Better to toe the line, get your studies funded, continue with your career advancement, and bash Steve M for bringing up uncomfortable facts. The “everyone knows which studies are good” statement is iconic, sad and pathetic.